1. Field of the Invention
This invention relates to an apparatus and method for producing extruded products, and particularly to incorporating longitudinal stripes onto extruded products useful in color coding the extruded products for identification, decorative, and other useful purposes.
2. Description of the Related Art
While this invention relates generally to extruded products, for purposes of illustration, references will be made to electrically insulating coatings for cable or wire. However, the invention is applicable to other products such as extruded pipe and other extruded products.
The outer jacket or insulative material of an electric wire or cable is formed by means of extrusion coating. It is well-known that many electrical conducting wires are jacketed and/or insulated with thermoplastic materials such as polyethylene, polyvinyl chloride, or nylon. Such materials may be applied to the surface of a wire by well-known extruding apparatus and methods using an extrusion apparatus designed for this purpose.
Methods and apparatus for producing striped cable are also known in the art. Stripes are often incorporated onto extruded products in order to identify such extruded products. For example, a wire or a cable may be run from one end of a building to another end and different color stripes help to identify the wires at the opposite end and prevent erroneous connections from being made.
Various methods of striping extruded products have been used in the past. For example, an ink striping method applies a stripe of colored ink to wire by means of a wheel running in an ink bath and transferring the ink to the surface of the wire coating, or alternatively, uses a needle running along the surface of the wire through which ink is forced through the needle and onto the coating. Another method of striping involves utilizing multiple extruders containing different colored materials to form a multi-colored or striped coating on the wire. In this method, the separate stripe extruder is often provided for the purpose of extruding one or more stripes on the surface of the jacket or insulating material of the conductor.
The current invention provides many advantages over the prior art. The current invention involves combining the step of extruding stripes onto an extruded product with the step of extruding a jacket and/or insulative materials onto the extruded product. The combination of these two steps eliminates time loss and costly logistics involved in extruding the stripes and the jacket and/or insulative material onto the extruded product in two separate steps. Additionally, the striping extrusion assembly of the current invention is adaptable to an existing extrusion apparatus and can be easily removed and placed onto another existing extrusion apparatus. The portable and exchangeable nature of the striping extrusion assembly provides for versatility and adaptability of the extrusion apparatus.